As the Air Force and the other services face an environment of decreased defense spending, they may have to work more closely together to develop the next fleet of unmanned aircraft.

Over the past 10 years, each military service has pursued its own unmanned aircraft program while making little effort at consolidating their various systems, according to the Congressional Research Service.

"It appears that great potential exists for duplication of effort," a January 2012 CRS report found. "This leads many to call for centralization of UAS [unmanned aerial systems] acquisition authority, to ensure unity of effort and inhibit wasteful duplication. On the other hand, if UAS efforts are too centralized, some fear that competition and innovation may be repressed."

Beginning in 2014, every Army division is set to get a company of Gray Eagles, which are similar to the Air Force's MQ-1 Predator but can carry four Hellfire missiles instead of the Predator's payload of two Hellfires. Each Gray Eagle costs about $6.6 million, including its sensor payload. A Predator and its sensors cost $4.5 million.

The Navy also is establishing its own squadron exclusively dedicated to flying the MQ-4C Triton unmanned aircraft — based on the Air Force's Global Hawk — that have a 130-foot wingspan and can spend 28 hours in the air.

But as budgets shrink, the services need to become more interdependent with regards to unmanned aircraft, said Air Force Lt. Col. Lawrence Spinetta.

The Air Force should lead the effort to develop such aircraft — not reduce its emphasis on them — because the service has the expertise on airpower, said Spinetta, who wrote an article last year in Armed Forces Journal arguing the Air Force was focusing on manned aircraft to the detriment of unmanned aircraft.

"We can't afford to have four different air forces," Spinetta said. "I don't know if you heard the old joke where we have an Air Force, of course, with an air force; a Navy with an air force; the Army has an air force — and even the Navy's army, the Marine Corps, has an air force. That's just untenable going forward in this fiscal environment."

For fiscal 2013, the Air Force has budgeted $553.5 million to buy 24 MQ-9 Reapers; $393.4 million for research, development, testing and evaluation; and $157.2 million to retain the Global Hawk Block 30 aircraft that Congress would not let the service retire.

Meanwhile, the Army has budgeted $879.3 million to buy unmanned aircraft; $329 million to operate them; and $109.8 million for research, development, test and evaluation; and the Navy budgeted about $1.3 billion to purchase, develop and operate unmanned aircraft, officials said.

Similar technologies

The wars in Iraq and Afghanistan have allowed the services to bypass the traditional procurement system and deploy unmanned aircraft directly to the field, prompting the Defense Department to be concerned.

At one point, the Army and Air Force were working on different payloads of sensors that were 80 percent common and manufactured by the same contractor, the Government Accountability Office noted in 2009.

"However, according to Army officials, the Air Force sensor is more expensive and has capabilities, such as high-definition video, for which the Army has no requirements," the GAO found. "Therefore, the Army does not believe a fully common solution is warranted."

The Predator and the Gray Eagle are essentially the same aircraft, Spinetta said. "They fly from the same runways; they're using the same airspace doing the same mission, supporting the same people," he said.

The services have a long way to go toward working together on unmanned aircraft, said retired Lt. Gen. David Deptula, former deputy chief of staff for intelligence, surveillance and reconnaissance.

"If we are going to meet the kind of severe resource constraints that everyone agrees are going to be ahead, then we need to take a much more joint and interdependent look at how we solve the challenges that still lie ahead for the optimal use of remotely piloted aircraft," Deptula said.

The Defense Department needs to put an executive agency in charge of developing unmanned aircraft to ensure they can share information among the different services and use common systems, Deptula said.

"We keep on doing it in a segregated fashion, where you've got services out there trying to develop a set of systems that they own all by themselves so they can be self-sufficient," he said. "That is the antithesis of jointness — and quite frankly, we're not going to be able to afford that kind of excess redundancy in the future."

Interoperability failure

Besides being costly, another consequence of producing unmanned aircraft for different services is they do not communicate well with one another, causing mission difficulties, the CRS report found.

"There have been some cases where a service's UAV, if it could have gotten data to another service, another component, it may have provided better situational awareness on a specific threat in a specific area that might have resulted in different measures being taken," the report quotes Dyke Weatherington, head of DoD's UAS planning task force, as saying.

Each service has its individualized needs for both manned and unmanned aircraft, so unmanned aircraft vary in size and range, from one pound to very large with more than a 100-foot wingspan.

Of the roughly 10,700 unmanned aircraft in the services' inventories, more than 9,500 are lighter than 20 pounds, according to Defense Department data. Most are 4-pound RQ-11 Ravens used by all of the services.

The larger unmanned aircraft, such as the Predator, Reaper, Global Hawk and Gray Eagle, make up about 400 aircraft. While the Army's Gray Eagle and the Air Force's Predator have many elements in common, the Gray Eagle has some significant advantages, such as a heavy fuel engine, redundant avionics, a payload capable of full-motion video and the ability to carry up to four Hellfire missiles.

"Additionally, Gray Eagle has a significantly improved communication system to meet Army Division level requirements, including a communications relay capability," said a Defense Department official, who asked to not be named because he was not authorized to speak on the record. "The Air Force is taking advantage of many Army-funded efforts, including auto-landing and take-off, de-icing and Ka-band SATCOM [satellite communications] as risk reduction efforts for future improvements to MQ-9."

But there are also real differences in how the services operate unmanned aircraft. The Air Force stations its remotely piloted aircraft operations in the United States, while the Army deploys them to theater. Depending on the aircraft, the Navy plans for capabilities to operate from in theater, off carriers and at Naval Air Station Patuxent River, Md.

"The Air Force believes that flying UAS from control stations in the United States will be attractive to some in the Reserve component who may be disinclined to experience an active-duty lifestyle consistent with flying manned aircraft," the CRS report found.

Another major difference: The Air Force requires pilots on some unmanned aircraft to be flight-rated officers, while other services do not, according to the report. The Navy is looking at creating an enlisted rating and requiring flight-rated officers for unmanned aircraft 55 pounds or heavier.

"This means that, in the other services, there is no competition between manned and unmanned aircraft for potentially scarce pilots," the report found.